This invention relates to a ground referenced stabilization arrangement for a radar system. More particularly, this invention relates to an arrangement for calibrating a radar system to a mounting platform gyroscope (gyro). Still more particularly, this invention relates to facilitating recalibrating the radar system each time the system is exchanged for maintenance or repair, or replaced, as the case may be.
When a radar system is mounted to an unsteady platform, such as a ship or an aircraft, it is desirable to properly compensate the pointing of the antenna for motion of the unsteady platform. The system antenna must be positioned so that the radar beam remains pointed at a target when the platform moves. When, for example, an aircraft is in a roll or pitch maneuver, the radar beam will be directed into the ground at certain points without proper stabilization. This can cause ground reflections to be confused with desired targets, such as other aircraft or weather formations.
A stabilization arrangement typically includes a gyro mounted to the same platform as the radar system. The radar system reads angular information provided by the gyro and provides inputs which are used to determine a required calibrating displacement to be applied to the radar system antenna. For the stabilization arrangement to work properly, the gyro outputs must be particularly calibrated to the radar system. In the typical stabilization arrangement, these particular calibrations are made directly to the radar system. Therefore, when the radar system is exchanged or replaced for one reason or another as is often the case, the calibration procedure must be repeated. This procedure involves mounting the gyro on a controlled mounting surface and adjusting radar system parameters such as, for example, pitch gain, pitch offset, roll gain and roll offset. This repeated calibration is costly, time consuming and disruptive as in the case of removing a sealed radome on an aircraft to perform the calibration, as will be appreciated.